Technical Field
The present invention relates to semiconductor devices and processing, and more particularly to devices and methods for doping a self-aligned punch through stopper to improve device channel performance.
Description of the Related Art
High Ge concentration SiGe is a promising channel material for performance improvements in p-type field effect transistors (PFETs) due to the expectation of high mobility. One problem in SiGe PFET fabrication is controlling punch through stopper (PTS) doping. PTS doping should include n-type dopants (such as, As, P, etc.). N-type dopants are known to have extremely high diffusivity in SiGe. This makes it challenging to control PTS doping below a channel region in bulk SiGe fin field effect transistors (finFETs).